SootScan™ Model OT21 Transmissometer
The SootScan™ Model OT21 Transmissometer bench top analyzer has been developed as a simple and robust way of assessing Black Carbon particulate matter (PM) from a variety of sample filters. The analysis can be easily performed in the field or the laboratory, and requires less than thirty seconds to provide optical attenuation and BC mass concentration results. This non-destructive analysis method requires no support gases or consumables. A neutral density photometric standard filter kit is available for verifying instrument calibration and validating the instrument response.
The SootScan™ is designed to analyze filters for Black Carbon content which are collected from both ambient and source applications. Since the method does not alter or destroy the sample during analysis, the OT21 method can be used to quickly determine BC from samples collected specifically for US EPA PM-2.5 Federal Reference Method (FRM), Method 5 / 201A stationary source, and mobile source compliance determination. Importantly, because Black Carbon PM is non-volatile, sample analysis can be performed on archived filters as well as freshly collected ones.
The instrument contains a 2 wavelength light source; 880nm providing the quantitative measurement of Black Carbon PM, and a 370nm for qualitative assessment of certain aromatic organic compounds. This 2 wavelength approach provides additional information which would be important for two main reasons: determining source apportionment of ambient PM samples (i.e. wood smoke vs. diesel PM) OR the health status of a diesel engine (i.e. blue smoke = leaky seal, black smoke = poor combustion efficiency)
The instrument is designed to directly accept 25, 37, or 47mm diameter filters comprised of Teflon, quartz fiber, glass fiber, or Teflon-coated glass fiber media. Alternative filter diameters can also be assessed by analyzing a "punch" of a larger sample (i.e. 8 x 10" high volume filter or 70mm or larger source sample filter).
An OCR digital imaging device / barcode scanner option is available for convenient data logging and sample chain of custody information transfer. Analysis results are displayed on the instrument's LCD screen and using the PC Interface Software included with the instrument, measurement data can be communicated electronically from the OT21 to a personal computer through a serial data connection.
Data transmitted to a connected PC is output in a .csv compatible format that is easy to import and manage in a spreadsheet application.